In a distributed control system, a plurality of remote units that control control-target devices are used with the number of the remote units being set according to the number of control-target devices, and each of the remote units has recorded therein operation information for determining operations unique to the corresponding remote unit. Accordingly, when a unit is replaced at a time when, for example, the remote unit is broken down, it is necessary to read the operation information from the remote unit or to read the operation information in advance and write, in a new unit, the operation information in the remote unit that has been replaced after the unit is replaced.
Examples of the operation information include setting information for operating remote units or adjustment information (such as an offset/gain value in an analog unit) for eliminating individual differences between units.
With regard to the above problem, there is proposed a method of writing operation information in remote units via a network (see, for example, Patent Literature 1).